PIPE

172.3 kJ

For an isometric process involving 3 kg of air, the temperature increases from 20°C to 100°C. Calculate the heat added (Cv=0.718 kJ/kg-K).

-200 kJ

In an isobaric process, 2 m3 of gas at 200 kPa is compressed to 1 m3. Calculate the work done.

0.1 m³

Air is compressed isothermally from 100 kPa and 0.5 m3 to 500 kPa. What is the final volume? A) B) 2.5 m3 C)

-80.5 kJ

Calculate the work done during the isothermal compression in Question 63.

128.9 kPa

A gas undergoes an isentropic expansion where P1 =600 kPa, V1=0.1 m3, and V2=0.3 m3. If k=1.4, find the final pressure.

64.8 kJ

Calculate the work done in the isentropic process in Question 65.

0.689 m3

A polytropic process (n=1.3) expands a gas from 500 kPa and 0.2 m3 to 100 kPa. What is the final volume?

Zero

In an isometric process, the work done is always:

Zero

For an ideal gas, the change in internal energy (ΔU) during an isothermal process is:

Isobaric

Which process is also known as "isopiestic"?

11.

A gas is compressed in a polytropic process (n=1.2) from 100 kPa and 25°C to 400 kPa. Find the final temperature. A)

100°C B) 91.5°C C) 125.4°C D) 146.2°C

12.

For an isentropic process, the heat transfer Q is: A) mcp ΔT B) PΔV C) Zero D) mcvΔT

13.

Calculate the change in entropy (ΔS) for 1 kg of air heated at constant volume from 300 K to 600 K. A) 0.498 kJ/K B) 0.718 kJ/K C) 0.250 kJ/K D) 0.981 kJ/K

14.

A piston-cylinder moves 2 kg of air isobarically at 300 kPa from 40°C to 150°C. Calculate the work. A) 63.1 kJ B) 120.5 kJ C) 45.2 kJ D) 94.2 kJ

15.

Find the polytropic specific heat Cn if Cv=0.718, k=1.4, and n=1.2. A) -0.718 kJ/kg-K B) 0.359 kJ/kg-K C) -0.359 kJ/kg-K & D) 0.718 kJ/kg-K

16.

In a throttling process, which property remains constant? A) Entropy B) Temperature C) Enthalpy D) Pressure

17.

An isentropic process is both: A) Isothermal and reversible B)

Adiabatic and reversible C) Isometric and adiabatic D)

Adiabatic and irreversible

18.

If 100 kJ of work is done ON a gas during an isothermal process, the heat transfer is: A) 100 kJ added B) 100 kJ rejected C) 0 kJ D) 50 kJ rejected

19.

The ratio of Cp to Cv is called: A) Gas constant B) Polytropic exponent C) Specific heat ratio D) Compressibility factor

20.

Calculate the change in enthalpy for 2 kg of air (Cp=1.006) when heated from 20°C to 120°C. A) 201.2 kJ B) 100.6 kJ C)

402.4 kJ D) 50.3 kJ

21.

When gas is heated at constant pressure, the process is called

A.isometric

B.adiabatic

C.polytropic

D. isobaric

22.

A group of 50 persons attend a secret meeting in a room which is 12 meters wide by 10 meters long and a ceiling height of 3 m. The room is completely sealed off and insulated. Each person gives off 120 kcal per hour of heat and occupies a volume of 0.2 m3. The room has an initial pressure of 101.3

kpa and temperature of 16oC. Calculate the room temperature after 10 minutes.

A.

36.35

B.

33.10

C.

23.24

D.

76.32

23. In a Diesel cycle, the compression ratio is 15. Compression begins at 0.1 Mpa, 40oC. The heat added is 1.675 MJ/kg. Find the MEP of the cycle. A. 1131. 4 Kpa.

B.

2131. 4 Kpa.

C.

3131. 4 Kpa.

D.

4131. 4 Kpa.

24. Consider two Carnot heat engines operating in series. The first engine receives heat from the reservoir at 2500oK and rejects the waste heat to another reservoir at temperature T. The second engine receives heat by the first one, convert some of it to work, and rejects the rest to a reservoir at 300oK. If thermal efficiencies of both engines are the same, determine the temperature T.

A. 849oK B. 578 oK C. 763 oK

D. 976 oK

25. In an ideal Brayton cycle has a net work output of 150KJ/kg and backwork ratio of 0.4. If both the turbine and the compressor had an isentropic efficiency of 80%, the net work output of the cycle would be.

A. 50KJ/kg B. 75KJ/kg C. 98KJ/kg

D.120KJ/kg

26.

A water reservoir contains 100,000 kg of water at an average elevation of 60 m. The maximum amount of electric power that can be generated from this water is:

A.8KWh B.16KWh C.1630KWh D.58, 800KWh

27.

The gain of entropy during isothermal nonflow process of 5 lb of air at 60℉ is 0.462 Btu/R. Find the V1/V2.

A. 3.85

B. 0.259 C. 1.0

28. An auditorium seating 1500 people is to be maintained at 80℉ dry bulb and 85℉ wet bulb temperature when outdoor air is at 91℉ dry bulb and 75℉ wet bulb. Solar heat load is 110,000 Btu/hr and supply air at 60℉, determine the amount of supply air. Sensible heat per person = 225 Btu/hr

A. 93,229.17 lb/hr

B. 83,229.17 lb/hr C.

D. 63,229.17 lb/hr

29. In a Brayton cycle that operates between temperature limits of 300K and 1773K wit k = 1.4, determine the temperature at the end of the compression (isentropic) for maximum work of the cycle.

A. 700K

B. 590.5K

30. Work done by a substance in reversible non flow manner in accordance with V = 100/P ft3, where P is in psia. Evaluate the work done on or by the substance as the pressure increases from 10 psia to 100 psia.

A.

33,157.22 ft-lb

B.

-33,157.22 ft-lb

31. A cylindrical flash tank mounted with its axis horizontal is used to separate liquid ammonia from ammonia vapor. The ammonia vapor bubbles through the liquid with 70 m3/min leaving the disengaging surface. The disengaging rate is limited to 60 m/min and the liquid level is to operate with the liquid level one-third of the diameter from the top. Determine the diameter if the tank is 1.5 m long.

A.

830 mm

B.

730 mm

32. A 150 Hp motor is used to drive a compressor. If the heat loss from the compressor is 25 kW and the mass flow rate of the refrigerant entering the compressor is 0.50 kg/s, determine the difference of the enthalpies between the inlet and outlet of the compressor.

A.

143.80 kJ/kg C.173.80 kJ/kg

B.

153.80 kJ/kg D.183.80 kJ/kg

33. Find the pressure at the 100 fathom depth of water in kpag.

A. 1,793.96 kpag

B. 1,893.96 kpag

D. 1,693.96 kpag

34. Find the work possess for a Helium gas at 200C

A. 609 KJ/kg B. 168 KJ/kg C. 229 KJ/kg D. 339 KJ/kg 35. Two kilogram of gas is confined in a 1 m3 tank at 200 kpa and 880C. What type of gas is in the tank?

A. Helium B. Ethane C. Methane D. Ethene

36. Find the enthalpy of Helium if its internal energy is 200 KJ/kg

A. 144 KJ/kg

B. 223.42 KJ/kg

37. Compute the mass of a 2 m3 propane at 280 kpa and 40˚C.

A. 6.47 kg

B. 5.1 kg

38. At the beginning of the compression stroke of an ideal Otto Cycle has an air pressure of 15 psia, a temperature of 75oF and a specific volume of 13.2 ft3/lb. At the end of compression, the specific volume is 1.76 ft3/lb. The heat supplied to the cycle is 352 Btu/lb. Calculate the highest pressure of the cycle.

A. 685 psia B. 785 psia C. 150 psia D. 345 psia

39. For steam power plants, decreasing the operating pressure of the boiler will

A.

increase thermal efficiency

B.

decrease thermal efficiency

C.

bring thermal efficiency to zero

D.

make thermal efficiency constant

40. Carnot cycle A, B and C are connected in series so that the heat rejected from A will be the heat added to B and heat rejected from B will be added to C, each cycle operates between 30 ˚C and 400 ˚C. If heat added to A is 1000 kw, find the work output of C.

A. 111.44 kw

B. 549.78 kw

D. 141.89 kw

41.

A 0.5 m3 tank contains Nitrogen at 200 kPa and 30°C.

Calculate the mass of the gas

A)

1.11 kg B) 2.22 kg C) 0.85 kg D) 1.54 kg

42.

Water flows through a pipe with a velocity of 3 m/s. If the pipe diameter is 10 cm, what is the volume flow rate? A) 0.0236 m3/s B) 0.0942 m3/s C) 0.0078 m3/s D) 0.0314 m3/s

43.

Air at 500 kPa and 100°C occupies a volume of 2 m3. If the volume is halved while the temperature remains constant, what is the new pressure?

A)

250 kPa B) 1000 kPa C) 750 kPa D) 1500 kPa

44.

A nozzle has an inlet area of 0.02 m2 and an exit area of 0.005 m2. If the inlet velocity is 10 m/s, what is the exit velocity for an incompressible fluid? A) 2.5 m/s B) 20 m/s C) 40 m/s D) 50 m/s

45.

Calculate the mass flow rate of oil (ρ=850 kg/m3) flowing at 2 m/s through a 50 mm diameter pipe. A) 3.34 kg/s B) 1.67 kg/s C) 5.12 kg/s D) 2.85 kg/s

46.

A gas at 100 psia and 80°F is compressed to 400 psia. If the process is isochoric, what is the final temperature in °F?

A)

320 °F B) 1600 °F C) 1700 °F D) 2160 °F 47. Find the gas constant R for a gas with a molecular weight of 44 kg/kmol.

A) 0.189 kJ/kg-K B) 0.287 kJ/kg-K C) 0.461 kJ/kg-K D) 0.208 kJ/kg-K

48.

A balloon is filled with 10000 liters of Helium at 101.3 kPa and 59°F. What is the mass of Helium? A) 1.69 kg B) 2.10 kg C) 0.52 kg D) 1.25 kg

49.

Oxygen at 25°C and 1 atm occupies 5 liters. If the pressure is increased to 3 atm and the temperature to 100°C, what is the new volume?

A) 1.67 L B) 2.09 L C) 1.25 L D) 2.50 L 50. Determine the density of Air at 2.96 atm and 122°F.

A) 3.23 kg/m3 B) 1.29 kg/m3 C) 2.15 kg/m3 D) 4.50 kg/m3

51.

A new temperature scale, the "Z-scale," marks the freezing point of water at -20°Z and the boiling point at 180°Z. If a substance is at 50°C, what is its temperature in °Z?

A) 80°Z B) 100°Z C) 120°Z D) 150°Z